BRUSSELS (Reuters) -Norwegian browser maker Opera filed a complaint about U.S. tech giant Microsoft to Brazilian antitrust authority CADE on Tuesday alleging its Edge browser has an unfair advantage, underscoring the long-running rivalry between the two companies.
Opera complained to the European Commission in December 2007 about Microsoft tying its Internet Explorer browser to its Windows operating system. The case eventually ended with a 561 million-euro ($648 million) EU antitrust fine for the U.S. company.
In July last year, Opera took the Commission to court for exempting Edge from the Digital Markets Act, which aims to rein in the power of Big Tech via a list of dos and don'ts.
In its complaint to CADE seen by Reuters, Opera alleged that Microsoft's pre-installation of Edge as the default browser across Windows devices and computers prevents rivals from competing on the merits of the products.
"Microsoft thwarts browser competition on Windows at every turn. First, browsers like Opera are locked out of important preinstallation opportunities," Opera's general counsel, Aaron McParlan, said in a statement.
"And then Microsoft frustrates users' ability to download and use alternative browsers," he said.
Microsoft had no immediate comment.
Opera, which said it is the third-most popular PC browser in Brazil, added that Microsoft's alleged tactics included giving incentives to major PC manufacturers to pre-install Edge exclusively on Windows on all their Windows devices.
Opera had 6.78% of the desktop browser market in Brazil in June, according to StatCounter, versus Edge's 11.52% while Google's Chrome held a commanding 75%.
Opera also alleged that Microsoft used anti-competitive measures such as design tactics or dark patterns to steer PC users away from rival browsers to Edge.
Opera called on CADE to investigate Microsoft and to demand concessions to ensure fair competition.
(Reporting by Foo Yun Chee in Brussels; Editing by Stephen Coates and Matthew Lewis)
